1. Field of the Invention
The present invention relates to a method of designing a fin-based transistor, and more particularly, to a method of designing a fin-based transistor for power optimization.
2. Description of the Prior Art
Conventional planar metal-oxide-semiconductor (MOS) transistor has difficulty when scaling down to 65 nm and below. Therefore the non-planar transistor technology such as Fin Field effect transistor (hereinafter abbreviated as FinFET) technology that allows smaller size and higher performance is developed to replace the planar MOS transistor.
The FinFET device is conventionally formed by: First a silicon layer of a substrate is patterned to form fin structures (not shown) by a proper etching process. A gate insulating layer and a gate conductive layer are formed and patterned to form gate electrodes covering portions of the fin structures. Next, dopants are introduced and annealing treatments are performed to form sources/drains in the fin structures not covered by the gate electrodes. Since the manufacturing processes of the FinFET device are similar to the traditional logic device processes, it provides superior process compatibility. More important, FinFET devices can be obtained by conversion of a planar design to FinFET design.
Furthermore, since the FinFET device increases the overlapping area between the gate electrode and the fin structures, the channel region is more effectively controlled. This therefore reduces drain-induced barrier lowering (DIBL) effect and short channel effect, and the current between the source and the drain is increased. Though FinFET design offers many advantages, there is still a demand for approaches that can improve performance characteristics of integrated circuits. For example, power consumption is one important aspect of the circuit performance. High power consumption in integrated circuits shortens battery life and reduces circuit performance and reliability. Therefore, a method of designing a fin-based transistor with power optimization is always in need.